How do I check to see if people are relaying mail from my server? I'm getting a lot of emails returned that I never sent.
You can check your server with e.g. the following tool, if its a open relay: http://www.abuse.net/relay.html Please post also the output of the command:
According to the site, all relay is denied. Code: mynetworks = 127.0.0.0/8 172.16.10.0/24 [::1]/128 [fe80::205:5dff:fe4e:1558]/64 mynetworks_style = subnet parent_domain_matches_subdomains = debug_peer_list,fast_flush_domains,mynetworks,permit_mx_backup_networks,qmqpd_authorized_clients,relay_domains,smtpd_access_maps proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks smtpd_client_connection_limit_exceptions = $mynetworks smtpd_client_restrictions = permit_mynetworks, reject_unknown_client smtpd_helo_restrictions = permit_mynetworks, check_helo_access hash:/etc/postfix/access, reject_invalid_hostname, permit smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,check_relay_domains
Could it be a 'joe-job'? Meaning your e-mail address is abused as the sender of spam and all the bounces are as such directed to you. Look at the headers of the emails (bounces?) you get. Tracing which systems are used might give you an indication.
I'm getting emails from a person whose mail I host -- mail that he's not sending. I did "postconf | grep mynetworks" and got the following: Code: # postconf | grep mynetworks mynetworks = 127.0.0.0/8 mynetworks_style = subnet parent_domain_matches_subdomains = debug_peer_list,fast_flush_domains,mynetworks,permit_mx_backup_networks,qmqpd_authorized_clients,relay_domains,smtpd_access_maps proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks smtpd_client_event_limit_exceptions = ${smtpd_client_connection_limit_exceptions:$mynetworks} smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
This is very common for spammers. This does not mean that the email was send trough your server. Spammers often use faked sender addresses.
